Examples of a conventional control device for a rotating element rotated by a four-stroke engine include a misfire detection device for an internal combustion engine disclosed in Patent Literature 1 (PTL 1) (identified further on). The misfire detection device for the internal combustion engine obtains an average rotation frequency ωn in explosion strokes of respective cylinders, based on outputs of a rotation angle sensor. Then, the device sets an average rotation frequency fluctuation amount Δωn by obtaining a deviation (first fluctuation amount (ωn−1-ωn)) between average rotation frequencies ωn in respective cylinders in which the explosion stroke successively occurs, and a deviation (second fluctuation amount (ωn−4-ωn−3)) between average rotation frequencies in respective successive cylinders at a rotation angle position 360°CA (crank angle) before. Then, the device determines a misfire based on the average rotation frequency fluctuation amount Δωn.
PTL 1: Japanese Patent Application Laid-Open No. H4-365958 (1992)